<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>通用兄弟选择器</title>

    <style>
        h3~p{
            color: brown;
        }
    </style>
</head>
<body>
    <p>我i是第0个元素</p>
    <h3>你好呀 我是标题</h3>
    <p>我i是第一个元素</p>
    <p>我i是第二个元素</p>
    <b>我是加粗内容</b>
    <p>好好好</p>
</body>
</html>